Known display types mainly include liquid crystal displays and organic light emitting diode (OLED) displays. Liquid crystal displays have advantages such as having a thin body, reduced power consumption, low radiation, and so on, as well as being widely used. Most of the liquid crystal displays on the market are backlight type liquid crystal displays. Each backlight type liquid crystal display includes a liquid crystal panel and a backlight module. Working principle of the liquid crystal panel is disposing liquid crystal molecules between two parallel glass substrates, applying a driving voltage using the glass substrates to control a rotational direction of the liquid crystal molecules, and then generating a picture by the light transmitted from the backlight module.
Thin film transistor liquid crystal displays (TFT-LCD) have been rapidly developed and widely used in recent years due to their advantages, such as low power consumption, excellent picture quality, and high production yield. Specifically, the TFT-LCD is a layer of liquid crystals sandwiched between the two glass substrates, with a color filter disposed on the upper glass substrate, and thin film transistors disposed on the lower glass substrate. An electric field variation is generated when the current passes through the thin film transistor, a deflection of the liquid crystal molecules is caused by the electric field variation, and thereby polarity of light is changed to achieve a desired display picture.
OLED display technology is different from traditional LCD display technology. For example, OLEDs do not require a backlight source, a very thin organic material coating is applied to the OLED, and the organic material coating is self-illuminating when current passes through it. The OLEDs have advantages such as having a high contrast, a wide color gamut, flexibility, a thin, light body, reduced energy consumption, and so on. In recent years, the OLED display technology has gradually become widely used in the field of mobile devices, such as smart phones and tablet computers, the field of flexible wearable devices such as smart watches, and the field of the large size curved-televisions (TV) and the field of white lighting. Momentum of the development of OLEDs is strong.
For the OLED displays, each pixel includes an OLED device and a pixel driving circuit driving the OLED device to emit light. As usage time of an OLED display increases, the OLED device gradually ages due to aging of the organic materials. After the aging, even if the same amount of current is passed through the same OLED display, there is a reduced display quality of the OLED display, resulting in mura (spots), and gradually decreasing display brightness.
In the prior art, aging compensation for the OLED monitor generally only applies to the display mura caused by the OLED monitor. However, it is unable to improve the problems of gradually decreasing display brightness and residual images.